Mr. Daniel T.W. Looi of Civil Engineering & Ms Ya-Huei Chang of Mechanical Engineering won the HKIE Outstanding Paper Award for Young Engineers / Researchers, while Dr. K.H. Lam got the HKIE Best Transactions Prize for 2015. Below are abstracts of their projects.
A Unified Shear Stress Limit for Reinforced Concrete Beam Design
Mr. Daniel T.W. Looi, PhD candidate under the supervision of Associate Prof. Dr. Ray K.L. Su at HKU’s Civil Engineering Department, are immensely researching in reinforced concrete (RC) and its mechanics under earthquake actions in low-to-moderate seismicity region including Hong Kong. In view of the high shear demand in many non-ductile RC members under seismic actions, they endeavoured to establish the appropriate shear stress limit in RC structures, starting with the most common form of RC member, ie. beams. Their work, published in the HKIE Transactions, “A unified shear stress limit for reinforced concrete beam design” was awarded the HKIE Outstanding Paper Award for Young Engineers/Researchers 2015.
The web crushing shear stress limit in reinforced concrete beam design concurring with the strut capacity in strut-and-tie method was found by testing series of asymmetrically spanned RC deep beams to unreinforced web crushing failure with varying concrete strength and strut angles. In this study, a unified shear stress limit model was proposed to anchor the maximum strut crushing limit and sectional shear stress in design codes via a generic shear enhancement factor. The proposed unified model exhibits modest conservatism compared to the Hong Kong Code of Practice for Structural Concrete 2013 and the Chinese Code for Design of Concrete Structures (GB 50010). The outcome of the research suggested that RC transfer beams, pile caps and corbels, which are typically accompanied by high shear demand, can be optimised in size to leverage construction material cost savings through the more relaxed shear stress limit.
An example of the crack pattern at failure of RC deep beams subject to maximum shear stress observed via Digital Image Correlation (DIC) technique and by manual crack plotting.
Stepwise Anodic Electrodeposition of Nanoporous NiOOH/Ni(OH)2 with Controllable Wettability and its Applications
Miss Ya-Huei Chang received her ph.D degree under supervision of Assistant Professor Tony Shien-Ping Feng in the Department of Mechanical Engineering, the University of Hong Kong in 2015. Her research focuses on the electrochemical fabrication of nanostructured materials and its applications on surface wettability and energy conversion. She received her B.S. and M.S. in Chemical Engineering from National Tsing-Hua University in 2005 and 2007 respectively. Prior to joining the University of Hong Kong, she spent four years (2007-2011) as project engineer working on dye-sensitized solar cells at Tripod Research Center in Taiwan.
Learning from nature with superhydrophilic/superhydrophobic properties, typically moss leaves and lotus leaves, inspires people to create various applications, such as self-cleaning, anti-icing, anti-fogging and anti-fouling. If the wettability-tunable coatings can also be kept transparency, the range of applications will be extended to optical fields such as focal-variable microlenses, anti-reflection films of solar cells and in-planar bio-microfluidic channels. A stepwise electrodeposition of nano-sponge NiOOH/Ni(OH)2 is developed to well manipulate the pore size and surface energy. By virtue of amorphous structure with short-range order feature, the nanoporous NiOOH can reversibly and rapidly switch wettability by alternate treatments of environmental chamber (superhydrophobic) and UV/ozone (superhydrophilic). The switchable mechanism of NiOOH/Ni(OH)2 pair arising from its exceptional intrinsic short-range order-disorder transition together with chemical composition change is highlighted for the first time. This distinct multifunctional thin film not only owns reversible wettability but also is optically patternable/repairable and electrically conductive, which would be applicable in the manufacturing of various micro- and nanostructures. We demonstrate this potential in the rewritable two-dimensional (2D) microfluidic channels.
A widely tunable wettability and non-degraded transparency of sponge-like nanostructured nickel hydroxide film is demonstrated for the transparent two-dimensional (2D) microchannels.
Photo taken at the ceremony for HKIE Outstanding Paper Award Young Engineers/Researchers 2015 at JW Marriot Hotel, Admiralty HK.
The HKIE Best Transactions Paper Prize
The HKIE Best Transactions Paper Prize has been set up to give recognition to outstanding papers published in HKIE Transactions since 1999. Three awards will be given annually if there are outstanding papers which warrant the awards prizes under three categories based on the generic areas of Civil, Mechanical and Electrical engineering. All papers published in HKIE Transactions will be automatically entered into the annual selection process of the HKIE Best Transactions Paper Prize. The selection process of the Prize is rigorous and papers are evaluated in terms of originality/innovation, clarity and logic of discussion etc by members of the HKIE Transactions Committee and the Transactions International Advisors.
Dr. K.H. Lam, whose paper was published in HKIE Transactions Vol. 21 No 2 entitled “Electricity consumption in Hong Kong: trend analysis and greenhouse gases emission", has been awarded the HKIE Best Transactions Paper Prize 2015. The paper was a result of his earlier collaborative research with other institutions.
